Free42 is a re-implementation of the HP-42S calculator and the HP-82240 printer.
It is a complete rewrite not using any HP code and it does not require an HP-42S ROM image.
Free42 is an Open Source project. The executables and source code are released under the terms of the GNU General Public License version 2.
All third-party code used in Free42 is either in the public domain or licensed under terms compatible with GPLv2 or used with the authors' permission.